Looking For a Personalization Plug-In

I have a client who has a ecommerce site on wordpress – we use cart66 pro and love it – – we saw that another personalization site has the ability for customers to upload their images and show proofs online (https://www.photogiftsbybagettes.com/) and now my client wants the same thing.

Does anyone know how they are doing this, and if there is a plugin that will do this same thing, or how I go about finding someone who can do this for us at a reasonable rate????

Thank you!